Q: I see recipes that specify either table salt or kosher salt. Is there really a difference?

A: At the most basic level, all salt - plain ol' table salt or fancy flakes of fleur del sel - is simply sodium chloride. The difference is in texture and the addition or lack of minerals.
Table salt is made with very fine grains. Minerals are removed, but it usually includes an anti-caking agent, such as calcium silicate. If it's iodized, iodine has been added to prevent thyroid diseases in regions where people's diets are low in iodine. Not all table salts are iodized, however.
Kosher salt comes from the same source as table salt, but it's made with larger grains. It's not necessarily a kosher product, but it's used in the process called koshering - removing blood to purify meat or make it kosher - because the larger grains dissolve more slowly and are better at removing moisture from meat.
Cooks like to use kosher salt because the larger grains make it easy to grab a pinch when you're cooking. It also doesn't have anti-caking agents, which could make brines cloudy.
You can swap the two in cooking, but taste carefully. Because table salt is finer, more grains will fit in a measuring spoon. So a recipe formulated to use kosher salt might be saltier if you make it with table salt.
(Email food or cooking questions to Kathleen Purvis at kpurvis@charlotteobserver.com.)